Anzeiger für Schädlingskunde, Pflanzenschutz, Umweltschutz (1998) 71, 88-93

W. Topp, J. Kulfan, S. Mergel and P. Zach (1998)
Massenvermehrung von phyllophagen Schmetterlingen in Laubwäldern des Rheinlands
[Mass occurrence of phyllophagous caterpillars in the deciduous forests of the Rhineland]
Anzeiger für Schädlingskunde, Pflanzenschutz, Umweltschutz 71 (5), 88-93
Abstract: We investigated species assemblages of Lepidoptera which feed on Quercus petraea, Carpinus betulus and Fagus sylvatica trees growing in commercial forests in the Rhineland (Germany). In total we found 63 different species of caterpillars. Several species (Operopbtera fagata, O. brumata, Tortrix viridana, Agriopis leucophaearia, A. aurantiaria and Erannis defoliaria) appeared in high abundances on oak trees, which they together defoliated.
Defoliation of Carpinus betulus as well as high feeding damages on Fagus sylvatica were caused mainly by a single species, Operopbtera fagata. From our observations of individual caterpillars and their extraordinarily high feeding damages (= 45%) on Fagus sylvatica trees which were growing in the shade of oak trees, in comparison to individual F. sylvatica trees not growing beneath oak trees (feeding damage = 7%), we made the following conclusions: Firstly, in the case of mass occurrence a severe influence of scramble competition occurs between caterpillars. Secondly, a prolongation of gradation of polyphagous caterpillars is caused when stratification by Fagus sylvatica living as undergrowth of oak trees occurs. Defoliated trees occurred in sites with enhanced nutrient availability. This supports the resource availability. hypothesis. Although there was a surplus of nutrients in the soil and within the roots we found a deficiency of P in the leaves.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
(original language: German)
Link to article at publishers website

Research topic(s) for pests/diseases/weeds:
surveys/sampling/distribution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Operophtera brumata	Oak (Quercus)	Germany
	Operophtera fagata	Oak (Quercus)	Germany
	Operophtera fagata	Beech (Fagus)	Germany
	Operophtera fagata	Hornbeam (Carpinus)	Germany
	Tortrix viridana	Oak (Quercus)	Germany
	Agriopis leucophaearia	Oak (Quercus)	Germany
	Agriopis aurantiaria	Oak (Quercus)	Germany
	Erannis defoliaria	Oak (Quercus)	Germany